Staple-forming machine



N V- 1 J. H. MOTT 2,910,697

STAPLE-FORMING MACHINE Filed Oct. 26, 1955 8 Sheets-Sheet 1 INVENTOR.

JOHN H M077 ///5 ATTOJHVEX Nm 3, 1959 J. H. MOTT 2,910,697

' STAPLE-FORMING MACHINE Filed Oct. 26, 1955 8 Sheets-Sheet 2 Ill Hm.

INVENTOR. JOHN H. #7077 BY I I a I 8 Sheets-Sheet 3 Filed 001;. 26, 1955 8 w 3 WU A 8 a, & o F 8 m m 8 m N\\ 6 w 1 8 5 7% m 0 W 0 2 Mm 7 6 7 7 m m 7 Q, 9 m a p M T N 0 I w; m.

Nov. 3, 1959 J. H. MOTT STAPLE-FORMING MACHINE 8 Sheets-Sheet 4 Filed Oct. 26, 1955 IN VEN TOR.

f filwm 0.0 0 V HI M Nov. 3, 1959 J. H. MOTT STAPLE-FORMING MACHINE 8 Sheets-Sheet 5 Filed Oct. 26, 1955 INVENTOR. Joy/v H M077 Nov. 3, 1959 J. H. MOTT STAPLE-FORMING MACHINE 8 Sheets-$heet 6 Filed Oct. 26, 1955 QJllllllllllllfl INVENTOR. JOH/Y M077" ///I firm/PW J. H. MOTT STAPLE Nov. 3, 1959 FORMING MACHINE 8 Sheets-Sheet '7 Filed Oct. 26, 1955 INVENTOR.

JO/M H M077 Nov. 3, 1959 MOTT STAPLE-FORMING MACHINE 8 Sheets-Sheet 8 Filed Oct. 26, 1955 INVENTOR. JOH/V 6 M0 77 United States Patent" 2,910,697 STAPLE-FORMING MACHINE John H. Mott, Upper Merion, Pa. Application October 26, 1955, Serial No. 542,822

12 Claims. (Cl. 12)

The present invention relates to staple-forming machines and is concerned primarily with a staple-forming machine that is adapted to be attached to a staple-driving machine.

At the present time "there are many types-of staple driving machines. One staple driver that is now, meeting with widespread use particularly in the field of packaging is the so-called retractable anvil stapling machine. Retractable anvil stapling machines are commonly employed where access may be had to only one side of the material being stapled, such as in the closing of cartons. This type of stapling machine uses what is known as an industrial staple. Such a staple is fairly heavy and is made from a flat wire. In accordance with presentday practice, staples are supplied to retractable anvil stapling machines in magazines which consist of long strips of preformed staples.

There are today many installations of retractable anvil staplingmachines which are automatic; thus, when a carton having one or more sets of flaps which are to be closed reaches the stapling station, one or more heads automatically engage the flaps and perform the stapledriving operations. With such automatic machines, it is evident that any given magazine of staples is quickly expended, and it requires the attention of an operator to replace them at frequent intervals.

With the foregoing conditions in mind, the present invention has in view as its foremost objective the provision of a staple-forming machine that is particularly adapted to be attached to and combined with a staple-driving machine.

More in detail, the invention has as an object the provision of a staple-forming machine that is adapted to be combined with a staple-driving machine in such a manner that the operation of the staple-forming machine is correlated and synchronized with that of the staple-driving machine. I

A somewhat more detailed object of the invention is to provide a staple-forming machine that is particularly adapted to be attached to and combined with a stapledriving machine of the retractable anvil type. Such a staple-driving machine utilizes an industrial staple, and

the staple-forming machine of this invention is particularly' adapted to making an industrial staple and forming this staple in proper relation with respect to the operation of the retractable anvil staple-driving machine.

In a retractable anvil staple-driving machine, a plunger is driven downwardly to carry out the various actions involved in the staple-driving operation. This plunger must be driven from an appropriate power source. While there are retractable anvil stapling machines of the manually operable type, there are also many automatic installations of such a stapling machine. One type of automatic installation now meeting with widespread use employs an air cylinder as the motivating force. The piston of this air cylinder is connected to the plunger of the stapling machineby a bell crank, a

I of the invention are associated with the provision of in Patented Nov .r3, 1959 With this conditionin mind, another highly important object of this invention, is to provide a staple-forming;

machine that is adapted to be attached to and com-Q binedwith a' staple-driving machine in such'a manner as to utilize the power source which operates the stapling machine for the motivating forcewhich operates the staple-forming machine. I p p r F r More in detail, the invention hasas an object the provision of a staple-forming machine that is adaptedto be attached to and combined with a retractable anvil stapling machine whichis operated from an air cylinder, with the staple-forming machine being operatively connected to the bell crank which connects the piston of the, air cylinder to the plunger of the stapling machineso as to be driven thereby. I

Another object of this invention is to provide a staple forming machineof the character indicated which forms staplesfrom a long strip of flatuwire that. iswound; into a reel orspool that is supported in, a position conveniently close to the staple-forming machine. From the very nature of the staple-forming operation, an appropriate length must be cut from this wire strip to form eachstaple. Moreover, it is to be remembered that the wire is heavy because industrial staples are to be formed therefrom. Thus, it is important that the end portion of thiswire be securely gripped and held while it is cut from the main body portion of the wire, and during the staple-forming operation. 1 i

With this factor in mind, a further objectof the invention is to provide in a staple-forming machine of .the characterindicated a mandrel over which the end portion of the wire is positioned as itis cut. Cooperating with this mandrel is a pusher which engages 'the edge of the wire under spring pressureand a pressure .bar which en-, gages the top surface of the wire and forces it against the mandrel under spring pressureasnthe wire is cut and formed. 5 5 1 5. 1 i:- Another object is to provide in .a staple-forming machine of the character indicated'a frameptogether with aslide that, is reciprocalin the framel This slide 'is connected to the bell crank, which connectsrthe piston of the air cylinder to the plunger-of the staplingmachine. Cooperating elements, of a. shearzare mounted onthe slide and frame, respectively, so as to cut off the end portion of the wire on each downward stroke of the slide.

Still another object of the invention is to provide in a staple-forming machine of the character aforesaid, forming elements which are carried by'the slide, and which cooperatewith the:mandrel to fashion the cutoff piece of wire into, the U-shape which is characteristic of an industrial staple. This U-shapeyprovides-a staple having aback and a pairoflegs depending therefrom. Industrial staples are ordinarily made from a steel wire having properties of resiliency, and elasticity. The. forming elements bend the legs. into, positions" substantially normal to the back. When these forming elements are removed, the resilient and elastic properties of the steel create a tendency for these legs to spring back into a position out of the perpendicular. This is undesirable. Thus, another object of the invention is to provide in a staple-forming machine of the character aforesaid a mandrel having aconcave top-surface in which the back of the staple is adapted to be forced during the staple forming operation to form a bowed or 'concave staple back. When thestaple-formingelements are removed, these same resilient and elastic properties are present in the concave back, and offset or counteract the tendency of'the legs to spread outwardly. Thus, a staple is ac? curately formed with the legs assuming the right-angular relation to. the-back. Particular objects and advantages strokeof' the 'slide. 'Onrthe upwardgstroke,the formed staple is "advanced towards the head of the-stapling machine a distance'o'fabout one half inch; which isin excess of the width of the staple, and i the wire again fed' into the machine its required length. An' important object of this invention is to provide instrumentalities which are operativelyconnected-to the 'slide for carrying out these operations.

'EMore in:detai1,"' theinventionhas as an'object the provisienaota staple-forming machine 'of the character indicateda'ndwhich includesa -mandr'el on W-hich is slid ably. rnounted ax usher. This pusher is of a U-shaped cross section"substantiallycorresponding to that of "a formed staple, and is spring-biased so that it'is normally urged" toward-thehead of the stapling machine. A lever has one end pivotally mounted in fixed position on the frameof" the machine and its other-.endis operatively connected to the slide. This lever carries abutment elements which are adapted to be engagedby certain cams soas to control the movements of the pusher.

Another object of the invention is to provide in a staple-forming machine of the type aforesaid a shaft thatais mountedin the frame and which isoperatively connected to? the slide. Surrounding this-shaft is a sleeve. A'apawl-and-ratchet mechanism-is employed to operative- 1y. :connect the sleeve to the shaft'only'onthe upstroke of the slide. This shaft and sleeve carry the cams aforesaid which engage theabutments on the lever andthus contrbl 'the'movernentzof the pusher.

I'Stll]. another object in view is toprovide in a stapleformin'grmachine of the type indicated,'a dru'rn which is disposed aboutcxthesleeve. .A'portion of this drum is formed as azfeedwheel which engages the-Wire from the supply. roll totfeeditwinto the rnachine when the drum rotates. A clock. spring -*has one end anchored to the drum and its other end to the sleeve. The drum-is held againstrotation/during thedownstr'oke and the'major part of the upstroke of. theslide, and during this upstroke therspring-is cocked or loadedso that-when it is released at the end .of the upstroke the drum' is rotated under-the influence of the spring to feed the wireto themachine. Important features of the invention are associated=with the mechanism provided forcontrollingthe operation of the drum.

:Various other more i detailed objects and advantages .of the invention such as "arise. in connection with carrying outlthe above-noted ideas inzapractical embodiment will in part become apparent and. inipart be hereinafter stated as the description of the inventionprocee'ds.

The invention rtherefore,'comprises astaple-forming machine that isadapted to be attached to and combined with a retractable anvil stapling machine, and which staple-formingmachine includes "a slide t hat'is actuated from'--thepower source of the'stapling machine, and which "slide'-o'peratesthe various instrumentalities which enter into and perform the staple-forming operation.

.For a;fulland more completeunders'tanding of the invention, reference maybe had to the following description and accompanying drawings wherein:

, Figure is a .bottomplan view of the staple-forming niachineof this invention as'appliedto' a retractable anvil staplingmachine Figurelis a verticallongitudinal section through the staple-forming machinewith the stapli-ng'rnachine shown in.elevation and withpartsin'the background omitted, and is .taken about'on the plane represented byitheline of Figure-1.

represented by the line 33 ofFigurel.

Figure 4 is a detailed vertical section through the mandrel, and is taken about on the planes represented by the lines 4-4 of Figure 2.

Figure 5 is a transverse vertical section taken about on the plane represented by the line 55 of Figure 1.

Figure 6 is another transverse vertical section taken about on the plane represented .by theline 66 of Figure 1.

Figure 7 is=still another transverse vertical section taken about on the plane represented by the line 77 of Figure 7.

Figure 8 is another transverse vertical section taken about on the plane represented by the line 8-8 of Figure 1.

Figure 9 is a detailed rear end elevation taken about on the plane represented by the line 99 of Figure 1.

Figure 10 is a detailed'horizontal section taken about on the'plane represented by the line10-'10of Figure 9; and

Figure 11 is a perspective view illustrating'the slide and 'certain of'theinstrumentalities that are associated therewith. This view is somewhat diagrammatic and does not' accurately conform to the proportions for purposes of' clarity.

The stapling machine porting bracket- 13 whichcarries an air cylinder 14. Con- .nected to thenpiston (not illustrated) of theair-cylinder .14.is a rod 15. The outer free end of this rod-15 is connected by links 16 toabell crank 17. The latter is pivotally mounted on a shaft 18 that issupported inopenings 19 in the supporting bracket 13 (see Figures 6 and 7). The. front end of the bell crank 17 is pivotally connected'as indicated at 21 to links 22 which sare-in turn pivotally connected to the plunger 12 as indicated at :23. It is evident that as the piston within the air cylinder 14 is reciprocated, the bell crank 17 isactuated to reciprocate plunger 12 and thus operate the stapling machine.

Frame of staple-forming machine The frame of the staple-forming machine is referred to in its entirety by the reference characterF. The frame F includes a pair of ears24 an dZS that are formed with openings which receive the opposite end portions of the shaft '18. Thus, the frame F ,is supported from the shaft18and by the head ltl-to which it is connected by the screws shown at'9. Extending downwardly'from the ear 24 there is a side wall '26, while a domelike walll27 extends outwardly from the ear'25. An L-shaped bracket having a vertical'wall28 and a'hor-izontal wall 29 .extends across the'fron't of theforming machine with the front edge 'of'the wall 29 abutting the head 10 and attachedto'head 10 as indicated at 30. This bracket wall 28-has an extension shown at 31 which extends out in front of the dome '27. I The frame also includes a vertical partition 'shown at '32 in Figure 2 and a rear wall '33. There isother wall structure that is connected to these parts that will later character M. This mandrel M has a vertical cross section somewhat similar to a hat that is definedbyatopwalhfl and side walls 35 from which outwardly extend flanges 36. The front end of the mandrel M is mounted on a block 37 that is secured to the rear face of the head immediately below the opening through which a formed staple is fed to the machine. The flanges 36 are secured to the frame by the screws shown at 38 in Figure 4.

It will be noted from Figure 2 that the mandrel M extends from the head 10 rearwardly past the-partition 32. Extending downwardly from the top wall 34 of the mandrel M is a spring anchor 39 to which is anchored one end of a tension coil spring 40 having a purpose to be later described. It is important to note that the top wall 34 is slightly concave, or in the form of a shallow V as illustrated. This enters into the formation of the staple, as will be later pointed out.

Slidably mounted on the top of the mandrel M is a pusher 41 of U-shaped cross section. This pusher carries a pin 42 which extends below the back of the pusher as shown in Figure 2 to constitute a spring anchor, and above the pusher as shown in Figures 9, 10, and 11, where it is adapted to be engaged by an operating lever as will be later pointed out. The tension spring 40 has its other end secured to this pin 42 as shown in Figures 2 and 9. Thus, the spring 40 normally biases the pusher 41in wardly toward the head 10. i e

The slide A slide which is an essential part of the staple-forming machine is referred to in its entirety by the reference character S. The slide S includes a main body portion 43 which operates between ball races 44 that are mounted on the frame wall 28. Extending upwardly from the main body portion 43 of the slide S is a tongue 45 which passesthrough an opening 46 formed in the supporting bracket 13 of the stapling machine. Pivotally connected to this tongue'by pin 47 are links 48 which are in turn connected to the bell crank17 by pin 49; Thus the slide S is operatively connected to the bell crank 17 to be actuated thereby.

The front face of the slide S is disposed closely adjacent to the frame wall 28. The rear face of the main body portion 43 of this slide is formed with a depression or recess 50 for a purpose to be later described. Extending outwardly from one side of the main body portion 43 of the slide is a wing 51 that is formed with an open mouth slot for a purpose to be later described;

Extending downwardly from the main body portion 43 of the slide are two legs 53 and 54 (see Figure 5) which are spaced apart a sufficient distance to appreciably clear the mandrel M.

An element of a shear is shown at 55 and is carried by a plate 56 that is secured to the frame wall 31. Cooperating with the shear element55 is a complemental shear element 57 that is mounted on the leg 54 of the slide. The lower edge of this element 57 also constitutes'a forming element as will be later described.

Another forming element 58 is carried by the leg 53 of the slide. i i t Referring now more particularly to Figure 2,- a bracket 59 has a foot 60 that is secured to the main body portion 43 of the slide S immediately above the recess 50. This bracket 59 extends rearwardly, downwardly, and then rearwardly again to provide an arm 61 on the free rear edge of which is pivotally mounted a bell crank 62 (see Figure 7). The bell crank 62 has two arms 63 and 64. The arm 63 is adapted to be engaged by an abutment pin 65 that is fixedly mounted on the frame F at the end of the downstroke. The arm 64 is adapted to. engage a drum-holding pawl 66 at the end of the upstroke, as will later become apparent. A U-shaped spring 67 has one end secured to the arm 64 as shown at 68 and its other end to the bracket 59 as shown at 69, This spring 67 serves to bias the. bell crank 62 and hold it on one side or the other of dead center.

Pressure bar A pressure bar is referred to in its, entirety by the reference characterP. It: is more clearly illustrated in Figures 2 and '11. Tliepressure bar P has the general construction of a bell crank. defined by a horizontal arm 70 that is pivotallymounted on a pin 71, which is in turn fixedly mounted in the frame F. Upstanding from the frontendofthbhorizontal arm 70 is a vertical arm 72, the upper end of which is bifurcated as indicatedat 73... The bifurcated end of the arm 72 carries a roller 74 which is adapted to rideover intofthe recess 50 of the slide S when the latter is moved down opposite to the roller 74. T e e The lower front edge of the arm 70 is formedas a rib 75 that is adapted to bear againstthe top face of thewire as the latter is positioned over thetop wall 34 of the mandrekM.

An adjusting screw 76 is mountedin a threaded opening in'the partition 32 and carries a pin 77 whichfunctions as a spring seat. Another spring seat 78 is carried by the arn1'72.; An expansion coil spring 79 has its opposite ends seated over the pins 77 and 78. This spring 79 exerts a tendency to urge the arm 72 forwardly and thus rotate the pressure barP about the pin 71 as ,an axis. This action is made possiblewhen the. roller 74 rides into the recess 50. When the roller is in this position, the spring 79 forces the rib 75 downwardly against the wire. 9 j:

It is evident that by adjusting the screw 76,. the effective tension of the spring 79 may be adjusted. With the rib 75 being slightly convex in a shape complemental to the concave top wall 34 of the mandrel M, it is evident that the back of the staple formed willfbe imparted a corresponding curvature. It isthe effective pressure of the spring 79 which determines the extent to which the back of the staple is bowed.

Shaft, sleejve, drum, and associated mechanism Referring "now more particularly to Figure 3, the frame F is shown as including a vertical wall 80 that is spaced from and located in alignment with the extension 31. A shaft 81 has one end journaled in the wall 33 and its opposite end reduced and journaled in theframe wall 80. Disposed about the shaft 81 is a sleeve 82 which is rotatably mounted on the shaft 81 through the medium of needle bearings shown at 83. The rear end of this sleeve 82 is enlarged into the cup-shaped formation illustrated at 84, and the free edge of the cup-shaped portion 84 is formed as a four-lobe cam 85. A second cam 86 is drivably mounted on the shaft 81 as illus trated at 87. The purpose of these cams 85 and 86 will later become'app'arent. j e p A drum is referred to in its entiretyby the reference character D. This drum D is rotatably mounted on the sleeve 82 through the medium of the ball-bearing assemblies indicated at 8. The drum D includes a feed wheel 88 which cooperates with a roller 8 9 that is carried by stub shaft 90 that extends inwardly from the frame wall 80. The wire, which is represented at 91,. passes between the roller 89 and the feed wheel 88; the moving force being. supplied by the feedwheel. 1

The drum D also includes a ratchet part 92. As shown in Figure 7, .the ratchet part 92 presentsfour shoulders 93, any one of which is adapted to be engaged by the free end of the drum-holding pawl 66. The latter ispivotally mounted at 94 on the frame F, and a tensioncoil spring 95 has one end secured to one end of the pawl 66 as indicated at 96 andfits other end to the frame of the machine as indicated at 97. This spring 95 normally biases the effective end ofthe pawl 66 inwardly into the position in which it engages one of the shoulders 93 to hold the drum against rotation. The pawl 66 is also formedwith a shoulder at 98 that is adapted to be engaged by the end of the arm 64 of the bell crank 62-so as to rotate the pawl 66 against the influence of the spring-95-.and release the effective end of the pawl from engagement with any shoulder 93 which it happens to abut.

through 90 and feed a required length of wvire' tothe machine." L p v v I M Referring nowmore 'pat'ticu'larl'y to igure 5, which may be considered alon'g'with Figure "3,the"shaft81' is shown as carrying a bell-crank-shaped le'verihaving arms 'The lever"103 carriesa pin 104 that'is "received in the 'slot 52 ofthe'wing"51"oftheslide. Thus, as'the slide S 'nioves up an'ddown, the "shaft' 81 is oscillated.

Carriedby the"sleeve"82' is' a ratchet "105. The arm 1 02, which "is *drivably" mountedon the "shaftsl, .has pivotally mounted onits free' end, as indicated at 1'06, a spring-biased -pawl 107,"'the free "end of which is adapted to en'gage one of the 'te'eth'of the 'ratchetllils. A locking dog 1'0'8 i's'pivotally mountedon' a pin "ltl9i-that :is carried by the frame wall 80. V

Itis evidentthat' on downward movementf'ofthe slide Sthe shaft"81 is rotated, but this motion is not imparted to the sleeve" 82"becat1se the pawl 107' simply rides over theteethottheratchetI05. "Moreover, the dog 1'08 definitelypreventsrot'ation of the'sleeve 82 in a counterclockwise direction (speaking with reference" to the showing'o'f Figure 5). However, upon upwardmovement of the slide S, the-pawl 10'7 engages one 'oftheteeth'of the ratchet -105 torotate the sleeve 82in asclockwiseidirection speaking with reference to the showing of FigureS).

Referrin nowmere:'partienlarlyto Fi ures9, 10, and l"1,""a'1ever1'10 is"shown"as' being pivotally mounted von on aipinill" that isfixedl'y secured to theframe F. 'The outer free end'oft'this lever. is slotted as shown at'11'2, with'the slofreceiVing'? the upwardly projecting 1 portion of .pin 42 that iscarried by the pusher 41. Acam-follower 'inthe form of a'roller'113 is mounted on ap'in114 that extends upwardly from the lever 110 and engages "thefour-lobe cam"85. An abutmentpin 115 is adjustably mounted in a'block 116 that is carried on the upper face of thedever 110. The inner end of this abutment pin 115 is" adapted to'be engaged by the cam 86. The cams 85 and 86, together 'with'the cam-fo'llower113 and abutment pin 115 through thelever 110, control and cause theoperation of the'pu'sher 41.

' 1 :Operation complete "operation will be'described,'beginning"with the downstroke. lt'rwillbe understoodthat, upon'the "start of -a downstro'ke 'o'f theslideS, a length of wire will have been fed into the'machine upon the termination of the previous cycle. This-lengthof wire'willextend across the top ofthemandrel in the'mannerdepicted in Figured =Du-ring the downward stroke, the sleeve 82 is. held against rotationby the 'dog"108. However, the shaft 81 is rotated. As thisrotation'commences, the'cam 86 leaves 'the end of the abutment pin 115, thus permitting thespring flllto urge theypusher 41 inwardly so that its innerend edge-engages the edgeof "the'wire "91 under pressure.

As downward movement ofthe slide is continued, the roller 74' of thepressure bar rides into the recess 50. vThis rendersthe spring-79 effective to force the rib 75 downwardly against the top face of the wire. The wire is now downwardmotion is. furthercontinued, the shear elements '55 and 57-cooperate to cutoffa proper length of the'wirc. Further downward movement causes the members 57 and 587to .function as forming elements whichishape the wire into the form of the finished staple, which is the conventional U-shaped construction. As the downward stroke is completed, the arm 63.of the bell-crank release 62 engages the abutment pin 65 to set the bell'crank in the position in which the free end of the arm' 64 will engage the shoulder 98ofthepawl '66 at the 'endof the upstroke.

At the start of the upstroke, the four-lobe cam--85 leaves the cam-follower113. However, at this'point the pusher 41 cannot move inwardly because the pressure bar P is firmly holding the formed staple. "HOWEVEIQ'WhCll the slide moves upwardly sufficiently far to cause the roller 74 to. ride out of the recess 50, the-pressure bar leaves the formed staple, and the pusher 41then moves this formed staple inwardly towards the head of the machine, thus moving the entire line of staples and one staple at the end of the line into the'head 10. The line of formed staples is held on the-mandrel M by a leaf spring 7 that is secured to the :undersideof the frame wall 29.

As this upwardvmotion of the slide takes place,'the sleeve 82 is rotated to cook 'or charge the spring 99. At the same time, the rotation of the sleeve causes the .fourlobe cam to begin the retraction of the pusher. This pusher must be gotten out of theway so that a new length of wire may be fed into the machine.

vAs the upward motion :of the slide is continued, the end '64 of the bell-crank 62 engages the shoulder 98 of the pawl 66 to knock the latter out of engagement with the shoulder 93 of the ratchet 92. Thispermits the drum to be rotated under the influence of the spring When the free endvof the pawl 66 clears one of the shoulders 93, it is again urged inwardly by the-spring soas to engage the next shoulder 93 and thus accurately limit rotation of the drum to 90. This 90?--rotation causes the feed wheel 88 to feed exactly: the required length'of wire to the machine. It is notable that as the pawl 66 .is knocked out of'engagement with the ratchet 92, the bell crank 62 engages pin 5 and is knocked overpast dead center and is held in this position by the spring 67. The pawl 66 is thus free to again be brought into engagement with the next ratchet tooth'93 by the spring 95;:while the bell-crank release 62 is again set at the end'of the downstroke by the abutment pin 65.

After the effective end of the pawl66 has been knocked outof engagement with one of the ratchet teeth 93, the opposite end of the pawl 66 will have been moved inwardly. In this position it will be engaged by the tooth 93 'just released to again set the'effective end of the pawl regardless of the action of the spring 95. This afiords definite assurance that the drum D will not rotate through more than90.

The machine is now in condition to have the. cycle repeated.

While a preferred specific embodimentof the invention is hereinbefore set forth, it is clearly to be-understood that-theinvention is not :to-be limited tosthe 'exacticonstructions, mechanisms, and devices illustrated :and described, because various modifications of thesedetails may be provided in putting'the invention intoprac'tice within the purview ofthe appended claims.

What is claimed is:

1. In a staple-formingmachine, a frame, a'rmandrel mounted in said frame, a slide mounted for reciprocal movement in said frame, pow'ermeans for actuatingsaid slide, wire-feeding means 'operatively. 'connectedrto :said

slide and adapted to feed aizlength of'wire .ioverisaid mandrel, apusherslidably mounted on said mandreliand adapted to engage an'edge of said wire'underspring pressure, apressure bar mountedrin'said frame'and adapted to engage thetop faceof saidwire-under spring pressure, cooperating elements of a shear onsaidslide -'an"d frame, respectively, and staple-forming elements carried by said slide and adapted to cooperate with said mandrel. 2. In a staple-forming machine, a mandrel having a shallow concave top wall and parallel side walls, forming elements adapted to bend a piece of wire over said mandrel into a substantially U-shaped formation including a back and legs, and a pressure bar for forcing the back of the staple into the concave top wall of the mandrel to impart a corresponding curvature thereto.

3. In a staple-forming machine, a mandrel having a shallow concave top wall and parallel side walls, forming elements for bending a piece of wire over said mandrel into-substantially a U-shaped formation including a back and legs, a pressure bar for forcing the back of said staple into the concave top wall of the mandrel to impart a corresponding curvature thereto, and adjustable spring means for actuating said pressure bar.

4. In a staple-forming machine, a frame, a mandrel mounted in said frame, a slide mounted for reciprocal movement in said frame, power means for actuating said slide, said slide having a main body portion, one face of which is formed with a recess, wire-feeding means operatively connected to said slide, a pressure bar of bellcrank formation pivotally mounted in said frame and having a rib at the lower front edge thereof adapted to engage the top face of the wire which has been fed into position over said mandrel, spring means normally urging the rib on said pressure bar into engagement with said wire, said pressure bar carrying a roller that cooperates with the main body portion of said slide and the recess therein to cause said pressure bar to operate in synchrony with reciprocation of said slide, cooperating elements of a shearon said slide and frame, respectively, and stapleforming elements carried by said slide and adapted to cooperate with said mandrel.

5. In a staple-forming machine, a frame, a mandrel mounted in said frame, a slide mounted for reciprocal movement in said frame, a shaft rotatably mounted in said frame, an operating connection between said shaft and said slide, a cam carried by said shaft, a spring-biased pusher slidably mounted on said mandrel, a lever pivotally mounted in said frame and connected to said pusher, a cam abutment carried by said lever and adapted to be engaged by said cam, wire-feeding means operatively connected to said shaft, cooperating elements of a shear on said slide and frame, respectively, and forming elements carried by said slide and adapted for cooperation with said mandrel.

6. In a staple-forming machine, a frame, a mandrel mounted in said frame, a slide mounted for reciprocal movement in said frame, power means for actuating said slide, a shaft journaled in said frame, an operating connection between said shaft and said slide, a cam carried by said shaft, a sleeve rotatably mounted on said shaft and having one end formed as a cam surface, a one-way driving connection between said shaft and said sleeve whereby said sleeve is rotated only on one stroke of said slide, a spring-biased pusher slidably mounted on said mandrel, a lever pivotally mounted on said frame and operatively connected to said pusher, a cam-follower mounted on said lever adapted to cooperate with the cam surface on said sleeve, an abutment pin on said lever adapted to cooperate with the cam on said shaft, wire-feeding means operatively connected to said sleeve, cooperating elements of a shear on said slide and frame, respectively, and staple-forming elements on said slide adapted to cooperate with said mandrel.

7. In a staple-forming machine, a frame, a mandrel mounted on said frame, a slide mounted for reciprocal movement in said frame, power means for actuating said slide, a shaft journaled in said frame and operatively connected to said slide, a sleeve rotatably mounted on said shaft, ratchet-and-pawl mechanism for operatively connecting said sleeve to said shaft for rotation in one direction only, a drum rotatably mounted on said sleeve,

a wire-feeding wheel carried by said drum, a ratchet also carried by said drum, a wound spring having one end anchored to said drum and the other end to said sleeve, a holding pawl pivotally mounted on said frame and having one end that is spring-biased into engagement with one of the ratchet teeth on said drum and an abutment shoulder, and a drum release carried by said slide and adapted to engage said abutment shoulder to move said pawl out of engagement with the ratchet tooth with which it engages to permit said drum to be rotated under the influence of said wound spring and feed a length of wire into position over said mandrel.

8. In a staple-forming machine including a frame and a slide mounted for reciprocal movement therein, wirefeeding mechanism comprising: a shaft journaled in said frame, an operating connection between said shaft and said slide, a sleeve rotatably mounted on said shaft, a

ratchet-and-pawl mechanism on said sleeve and shaft, respectively, for rotating said sleeve from said shaft in one direction only, a drum rotatably mounted on said sleeve, a roller cooperating with said drum in receiving wire to be fed between said drum and roller, a clock spring having one end anchored to said drum and the other end anchored to said sleeve, a feed wheel carried by said drum, a ratchet carried by said drum andhaving a plurality of teeth, a holding pawl pivotally mounted on said frame and having one end adapted to engage any one of said ratchet teeth on the drum, a spring associated with the other end of said pawl and mounted on said frame for urging said pawl end into position in which it is engaged by a ratchet tooth on the drum, an abutmentshoulder on said pawl, and a drum release mounted on said slide and adapted to engage said abutment shoulder to knock saidpawl out of drum-holding position. g

9. In a staple-forming machine, a frame, a mandrel mounted in said frame, a slide mounted for reciprocal movement in said frame, power means for actuating said slide, a shaft journaled in said frame, a driving connection between said shaft and said slide, a cam carried by said shaft, a sleeve rotatably mounted on said shaft and having one end formed as a cam surface, a ratchet carried by said sleeve and having four ratchet teeth, a dog pivotally mounted on said frame and having an effective end adapted to engage one of said ratchet teeth to prevent rotation of said sleeve in one direction, a pawl carried by said shaft and adapted to engage one of said ratchet teeth to rotate said sleeve from said shaft as said shaft rotates in the opposite direction, a drum rotatably mounted on said sleeve, a clock spring having one end anchored to said drum and the other end to said sleeve, a wire-feeding wheel carried by said drum, a second ratchet carried by said drum having ratchet teeth, a second pawl pivotally mounted on said frame and having an effective end springbiased into position engaging one of the teeth of said second ratchet, an abutment shoulder on said pawl, a springbiased bell crank mounted on said slide and having one arm adapted to engage said abutment shoulder to knock the effective end of said pawl out of holding engagement with said second ratchet, a spring-biased pusher slidably mounted on said mandrel, a lever having one end pivotally mounted in said frame and the other end connected to said pusher, a cam-follower on said lever adapted to engage the cam surface on said sleeve, an abutment pin on said lever adapted to be engaged by the cam on said shaft, cooperating elements of a shear on said slide and frame, respectively, and staple-forming elements carried by said slide and adapted to cooperate with'said mandrel.

10. In a staple-forming machine, a frame, a mandrel mounted in said frame, a slide mounted for reciprocal movement in said frame, power means for actuating said slide, a shaft journaled in said frame, a driving connection between said shaft and said slide a cam carried by said shaft, a sleeve rotatably mounted on said shaft and having one end formed as a cam surface, a ratchet carried by said sleeve and having two ratchet teeth, a dog said shaft and adapted to engage one of said ratchet teeth torotate said sleeve from said shaft as said shaft rotates in the opposite direction, a drum rotatably mounted on said sleeve, a clock spring having one end anchored to said drum and the other end to said sleeve, a wire feeding wheel carried by said drum, a second ratchet carried by said drum having ratchet teeth, a second pawl pivotally mounted on said frame and having an effective end springbiased into position engaging one of the teethof said sec- .ond ratchet, an abutment shoulder on said pawl, a springvbiased-bell crank mountedon said slidejand having one arm adapted to engage said abutment shoulderito knock the effective end of said pawl out of holding engagement frame and havinga rib at its lower front edge adapted to engage :the wire which has been fed over said mandrel, andan adjustable spring for actuating said pressure bar, said pressure bar and slide having cooperatingqelernents controlling theoperation of said pressure bar.

11. In a staple-forming machine including a reciprocal "slide-and a spring-biased wire-feeding drum normally held against feeding rotation, a roller cooperating with said drumin receiving wire to be fed between said drum and roller, a release in the form of a'spring-biased belLcrank mounted on said slide and having one arm adapted to affect said drum to cause its feeding rotation.

12. In a staple-forming machine, a frame, a slide reciprocally mounted in said frame, power means for actuating said slide, a drum, a wire-feeding wheel carried by said drum, a roller cooperating with said wheel ,in

receiving a wire to be fed between said wheel and roller, ratchet mechanism including a pawl normally holding said drum against rotation in a feeding direction, aclock spring associated with said drum andv adapted to be loaded upon movement of said slide, a spring-biased bellcrank mounted on said slide and having one arm adapted toengage said pawl to release said drum and :permit feeding rotation of said feed wheel, and an abutment pin carried by said frame and adapted to be engaged by the other arm of said bell crank to set said bell crank into position in which the first-mentioned arm will engage said .pawl.

References Cited in the file of this patent UNITED STATES PATENTS Blumensaadtuu, Nov. 13,1951 

